What did Slavic pagans believe about waters? Did they worship a god of the sea, or believe in nymphs and naiads? Who are the Rusalki? Where do the forgotten dead live in the afterlife? What role do waterways play in Slavic folklore? These are all questions asking about how the pagan Slavs viewed the land around them, how their animistic beliefs informed their understanding of their geography, and how they believed their mythology mapped onto the landscape.
“Waters” here is taken most generally: rivers, lakes, springs, oceans, waterfalls, creeks, etc. Slavic folklore furnishes us with countless tales and beliefs about these bodies of water and the beings that dwell below the surface.
A good starting point for reconstructing Slavic pagan beliefs about waters can be found in other pagan reconstruction projects. The Larhus Fyrnsida clearly explains the concept of liminality:
Liminal comes from the Latin word ‘limen’, meaning ‘threshold’ or ‘doorway’. Liminal is that which occupies the transitional space at a boundary or threshold. Geographically speaking, bridges, springs, crossroads, caves and rivers possess liminal characteristics and function as a gateway to new or different locations. When one enters the mouth of a cave, they are leaving the outside behind and entering a dark, subterranean world and when one crosses a bridge, there is a clear distinction between the area of origin and the destination.
Liminality transcends geography and can also be used to describe transitions in time or status, with New Year’s Eve and New Year’s Day being a prime example of a liminal period between two distinct years. Likewise, the period of twilight represents a liminal period between day and night.
Deities and spirits can also be liminal themselves, by occupying some intermediate space between worlds. A great deal of the liminal beings in Slavic mythology and folklore are associated with bodies of water, because of the persistent Slavic belief that bodies of water marked boundaries between the world of the living and the dead . This belief in the liminality of both inland waters and the sea is the reason for the significance of water to Slavic paganism in both belief and practice.
Waters and Sacred Spaces
We know from the accounts of chroniclers that pagan temples at Radegast (Rethra) and Wolin, both in modern Poland, were surrounded by bodies of water: swamps, moats and lakes . Chroniclers tell of local beliefs about spirits in these waters, and we can speculate about their use in ritual: bathing and sacrificing in these waters during holy times of the year.
Veneration of springs is a well known in Slavic cultures and persists even to this day, in the form of cults of Christian saints, in many rural areas. But this practice is certainly ancient; aside from the desire for the health benefits of mineral water, springs were either the object of worship or accompanying shrines to gods among Slavic pagan tribes living near the Elbe river.
The Głomacze tribe’s spring was famed for its fortune-telling: it was coated with acorns, oats or wheat to predict peace, and ash or blood to predict war . Acorns covering these waters meant nearby oaks to drop them: oak being a sacred symbol of the thunder god, Perun. Similarly, in Szczecin, a fountain at the base of a large oak tree was venerated as a shrine, to which god the chronicler does not name, but we might speculate it to be the thunderer .
Some waters were themselves personified or considered sacred and worthy of sacrifice. While river worship might not be as elaborate in Slavic paganism as Roman or Egyptian religion (worship of the Tiber or Nile, for example), we have examples of offerings being made to rivers during construction of bridges, and testimony of Arab travelers that humans were sacrificed the Elbe river . Also, the fairy tale “The Two Rivers”  tells that the Volga and Vazuza river race to the sea, that the Vazuza ‘wakes up’ first in spring but her sister carries her to their final destination. These personifications show that in the Slavic pre-Christian or folkloric worldview, rivers themselves, aside from just the spirits that dwell within them, could also be worshiped.
The sea itself may have been seen as sacred to Slavic pagans. According to Saxo Grammaticus, in 1160, the pagans on the island of Rugen agreed to their treaty with the Danes by throwing a stone into the Baltic Sea. As the stone hit the surface, they swore their oath . The Baltic Sea in fact may have been so sacred to the pagan peoples living around it – Baltic, Slavic, Finnic and Norse – that in the year 1000 according to Thietmar, the newly appointed Bishop of Kolberg also through stones into the waters and prayed that it be purified of ‘demons’ . This stone-throwing ritual seems to be an archaic form of veneration of the sea, which was reinterpreted in a Christian form.
We also know from archeology of the prevalence of ancient burial sites in northern Poland nearby rivers, lakes and springs . The sacred resting places of the dead traditionally were not far from bodies of water. This brings our attention to the complex chthonic aspects of Slavic beliefs about water: their association with death and the dead, but also fertility, healing and magic.
Boundary Between the Living and the Dead
Waters, and especially rivers, in Slavic myth and folklore demarcate the realms of living and dead. The Slavic word for land of the dead, navь, is etymologically related to Sanskrit nuah and Latin navis, both meaning “ship” . In this sense, waters are both transitory for both physical and spiritual vessels: boats and souls. Burial grounds near rivers and ship burials (often not as extravagant as, but including, ibn Fadlan’s viking funeral) have been discovered by archeologists . A common folk custom in Pomerania involved pouring out water across bridges to keep spirits and souls of the dead from crossing .
Further, many chroniclers describe Slavs upon Christianization drowning their idols in rivers . This includes the idol of Perun both as Kiev and Novgorod in the Primary Chronicle. These new converts show through their Christian piety the lingering Slavic mythical worldview: that the inland waters represented a gateway to the land of the dead, ‘hell’, to which they could cast their demons.
Rivers, springs and riverbeds are the traditional dwelling place of the Rusalki (singular: Rusalka; Russian: Русалки). These feminine spirits are the souls of ‘unclean dead’: those who die unnaturally or whose remains are unceremoniously buried . Left out from ancestor veneration, these souls retreat to the border between the world of the dead and the living.
The chronicler Ebbo describes a merchant who thanks Triglav for saving his life as sea, pointing to the possible aquatic and chthonic aspects of the Western Slavic deity . The idea of being saved from the sea by a god possibly reappears in Russian folklore. In the story of “The Sea King and Vasilisa the Wise” , a king finds an eagle sitting beneath an oak and raises it by feeding it cattle (the eagle, oak and cattle all being symbols of Perun). The eagle promises to repay the king. After growing to a great size, he flies the king around the world and ends up throwing him into various oceans. Afterwards, he explains that he helped the king ‘lose his fear of death’ through their journey.
While literally the king was afraid of drowning, death by water stands in for all death for the king. This fairy tale shows the persistence of the view of water as the boundary of life and death in Russian folklore, and the role of a (possibly) divine figure in protecting Slavs at sea.
Water Deities and Spirits
In Slavic pre-Christian religion, deities such as Veles and Mokosh along with the souls of the dead are associated often with water. Veles especially was known to dwell in swamps. In Czech folklore, his home “virij” was often said to be at sea . As his Christianized St. Nicholas in South Slavic folklore, he is the patron of the sea, sailors and fishermen . We can put these associations into context by remembering the liminal and chthonic aspects of waters in Slavic myth: Veles, as the primary liminal and chthonic deity in Slavic paganism, is right at home among the waters of the dead.
Besides these deities, two spirits in Slavic folklore stand out: Rusalki and Vodyaniki.
The Vodyanik (plural: Vodyaniki; Russian: Водяник) is a spirit of mostly northern Russian folklore . This spirit, which can be either the masculine Dedushka (Grandfather) Vodyanoi  or the feminine Vodyanucha  was seen as a “master of waters” . It is described as an elderly man or woman, variously bald  or with long, dark green hair . Unlike the Rusalka, the Vodyanik are not restricted from traveling away from their waters : they can shape shift to appear as humans. Folklore says that if the Vodyanik buys lots of corn when traveling, it means a bad harvest is coming ; this points again to the predictive power of waters in Slavic myth. Horse, cow, honey and butter were offered to the Vodyaniki.
The Rusalka, as mentioned before, are the feminine souls of the ‘unclean dead’ dwelling within inland waters. Often glossed as “Slavic mermaids”, these spirits played a complicated role in Slavic pagan animism and fertility cults, most prominently in Southern Russia, Ukraine and Belarus . Restricted only to leaving their waters during “Semik” (Russian: Семик) or “Rusalka Week” (Russian: Русальная Неделя) near the summer solstice, these spirits are known for seducing and drowning young men. They are the reason for prohibitions on washing or swimming in rivers and lakes until St. John’s Day (Russian Ивана Купала), which are held in both East and West Slavic folklore  .
While not entirely malicious, these spirits were not always welcome among Slavic pagans in ancient times. Often, houses near bodies of water would carve idols at the gates of their properties to defend against water-spirits . During Semik, wreaths hung on doors kept wandering Rusalki away .
Waters are one of the most prominent liminal realms in the worldview of Slavic mythology and folklore. For this reason, the prominently featured in or around temples, shrines, cemeteries and other sacred spaces. Slavic pagans understood these waters to be the limits of the world of the living, and for this reason prohibitions on or mass ritual bathing in these waters played a key role in the summer holidays Semik and Ivana Kupala.
This understanding of waters can inform contemporary Slavic paganism: what we believe and how we practice. Rivers, lakes and seas, we believe to be both deadly and lively, magical and to be feared. They are a place where Veles is strong, and it would be appropriate to worship him nearby (with proper offerings left for the hospitality of the Vodyaniki, and perhaps prayers to Perun for defense against the Rusalki), leaving sacrifices in the waters.
If you live near waterways or the ocean, it might be worth keeping an idol or icon of your Domovoi (house spirit) or patron deities near the doorway, to keep the water-spirits at bay. But at the same time, it could be valuable in your practice to engage in a gifting cycle with the Vodyaniki if you spend a lot of time on the water or nearby. Worshiping creeks, rivers, lakes or oceans themselves could also be a valuable practice to Slavic pagans on the water.
Remembering the dangers of the waters as a gateway to death, modern Slavic pagans can incorporate the cult of waterways and water-spirits into their practice based on these beliefs of ancient Slavic mythology and folklore.
 “Water in the pre-Christian beliefs of Pomerania (Northern Poland) of the early medieval period”. Kamil Kajkowski and Andrzej Kuczkowski. Studia Mythologica Slavica. 2017. p. 22, 24
 Ibid, p. 22
 ibid, p. 21
 ibid, p. 25
 ibid, p. 24
 “Rusalki: Anthropology of Time, Death and Sexuality in Slavic Folklore”. Jiří Dynda. Studia Mythologica Slavica. 2017. p. 88
 “The Sea King and Vasilisa the Wise”. Russian Fairy Tales. Aleksandr Afanas’ev. Trans. Norbert Guterman. The Pantheon Fairy Tale and Folklore Library. 1973. p. 428-9
 “The Two Rivers”. Ibid, p. 172
 Kajkowski and Kuczowski, p. 26
 Dynda, p. 87
 “Water-Spirits”. Mythology of All Races: Celtic and Slavic. Jan Machal. 1918. 2008 Web. p. 271
 Dynda, p. 86
 ibid, p. 96-97
 Kajkowski and Kuczowski, p. 17
 “New Insights on the Slavic God Volosъ/Velesъ from a Vedic Perspective”. Milorad Ivanković. Studia Mythologica Slavica. 2019. p. 58-59
 ibid, p. 60
 Kajkowski and Kuczowski, p. 18
 Dynda, p. 97